Often, people forget where they have parked their vehicle. Especially in a large shopping mall parking lot, or at a large sporting arena parking lot, the task of finding your car can become quite difficult to perform. A person cold spend a lot of time trying to find there vehicle, which could become severely annoying if weather conditions are not favorable, and could even become dangerous if the individual is attempting to evade another person chasing them.
Devices do exist to solve the problem of locating the position of a vehicle if the user has forgotten the vehicle's location. Some inventions have used visual displays, like U.S. Pat. No. 6,203,181, to assist the user in finding the position of their vehicle. These methods are disadvantaged when the user located out of the visual range of the vehicle, or if the user's vehicle is parked in between two larger Sports Utility Vehicles and can not be seen easily.
In invention of Global Positioning Systems (GPS) have brought about devices to solve the problem of being able to locate a vehicle. But methods using GPS, such as U.S. Pat. No. 6,363,324, carry the burden of both preprogramming the position of the vehicle before the user leaves the area that the vehicle is located. This requires the vehicle's user to remember to preprogram the GPS every time that the user leaves the car, or requires an additional device to constructed that programs the location of the vehicle for the user. Also, most GPS are large and bulky devices that can be uncomfortable to be carried by the user and demand extraordinary power supplies.
Radio frequency transponders are also used to perform the function of locating a predetermined object, such as U.S. Pat. No. 5,686,887. Again, the main disadvantage to this method is the size of the equipment and power supply needed to carry out the function of locating a remote object with radio frequency. This method of using radio frequency is also disadvantaged because radio waves are supervised by the Federal Communications Commission and require special permits to be used.
A second major disadvantage of many the prior art, is how the devices communicate the location of the object the device is locating to the user. Many devices, such as U.S. Pat. No. 5,710,548, display only the direction the predetermined object is located in from where the user is located. Whereas the invention disclosed within this application provides the user with a display communicating both the direction and distance to where the predetermined object is located from the where the user is located. This enables the user to be led by the device to where the predetermined object is, as opposed to only being pointed in the right direction of the position of the predetermined object.
A third prior art that is very similar to the disclosed invention is U.S. Pat. No. 5,606,325. This invention is a different solution to the same problem that the present invention is solving. It includes a hand-held device that on request sends out a signal that is received by a predetermined stationary device that returns a signal back to the portable device that then displays the direction of the thing the user is searching for to the user. There are two characteristics that separate this invention and the present invention being disclosed. The first is that the previous device displays only a direction display to the user to assist in finding the thing they are searching for, while the present invention provides a gauge to measure range to the object.
Secondly, the way that the previous invention operates is different and more complicated, and therefore more inefficient and costly then the present invention. The previous invention sends a signal from its portable device to the stationary device. Then the stationary device determines the absolute direction from where the signal originated, and then replies to the portable device with a specific predetermined signal indicating the absolute direction towards the stationary device. So, using cardinal directions to describe an example of how the prior invention operates, if the signal from the portable device originated South of the stationary device, then the stationary device will transmit a North signal to the device to display to the user. The same example applies to if the portable signal originates it's signal to the East of the stationary device, then the stationary device will transmit a West signal to the portable device.
The present invention being disclosed improves on this method by simplifying the signal transaction process. Instead of the stationary signal receiving the portable device's signal and determining the direction from where the signal originated, the stationary device simply reply's back to the portable device by emitting a simple and coded reply signal. A plurality of microphones located on the portable device intercept the reply signal and the order the microphones intercept the signal determines the direction of the stationary device. Thus, eliminating two steps in determining the portable signal's direction from where the stationary device is located and the need to transmit a specifically coded signal back to the portable device, which then has to interpret the specific signal and display the signal's matching signal.
Plus, the prior art's method, sends the portable device a signal indicating the absolute direction of the portable device to the stationary object. This method demands that the user using the device must remain in one location while searching for the stationary object in order to receive the most accurate account of the stationary object's location. This disadvantage confine the user, for example, if the user is being chased and needed to locate the safety of their vehicle, or if the portable device's power is out of range from where the vehicle is located. The method of the present invention allows the user to be mobile, because the direction indicators are located with the portable device being carried by the user. So, when the coded signal is intercepted by the portable device, the portable device is able to provide the user with the direction towards the user's vehicle at that moment, rather than the direction of the user's vehicle when the portable device had sent the signal.
In addition to the above improvements, the less steps taken by the present invention over the prior invention allow for lest electrical processing, which yields less materials needed to manufacture the device and it is therefore less expensive to produce.
Also, the present invention's method of determining direction by using a plurality of microphones allows for the possibility of determining distance from the portable device to the stationary device, which is a function the prior invention cannot perform. The method of how the plurality of microphones included on the portable device, determine the signal's distance is described in further sections.